There are now four candidates jostling for the position of Conservative leader, after seven were knocked out or stepped down.
Here are the politicians still in the running.
Environment secretary Michael Gove finished third in 2016, and is expected to campaign as a compromise candidate between Brexiteers and Remainers.
He’s promised to allow EU nationals who were living in the UK during the referendum to apply for citizenship free of charge if he becomes PM.
Mr Gove was a figurehead of the Vote Leave campaign along with Boris Johnson, and is also a supporter of Mrs May’s Brexit deal.
Jeremy Hunt announced he'll run for the Conservative Party leadership, only hours after Prime Minister Theresa May's Downing Street speech.
Speaking at the Haslemere Festival in south west Surrey, he said “it is only right that my party constituency should be the first to know”.
He's warned the Tories would be committing "political suicide" if it tried to push through a no-deal Brexit.
Home secretary Sajid Javid has put delivering Brexit “first and foremost” in his campaign.
In a video posted online he said it’s important to “restore trust, bring unity, and create new opportunities across the UK”.
He is the first person of Asian origin to stand for the job of Tory leader and Prime Minister.
Former foreign secretary Boris Johnson is the overwhelming favourite with bookies to become the next Conservative leader.
He told insurance brokers at a conference in Manchester: “I’m going to go for it. Of course I’m going to go for it.”
A number of politicians have already announced their support for Mr Johnson, including European Research Group members Jacob Rees-Mogg and Mark Francois.
Boris' dad Stanley Johnson told talkRADIO he would also be backing his son for PM.
"What other candidates are there out there who have had two terms as Mayor of London and demonstrated huge election-winning capacity?", he said.
Who is out of the race?
Rory Stewart made it clear he was interested in throwing his hat in the ring as Conservative leader with a newspaper article titled 'Why I’d make a good Prime Minister'.
The international development secretary was a big supporter of Mrs May's divisive Brexit deal, which may work against him as the party seeks to move on from the past three years of uncertainty.
Mr Stewart was knocked out in the third leadership vote.
The former Brexit Secretary has an online fan club that say they’re 'Ready For Raab'.
He received backing from several MPs before he officially joined the race.
Mr Raab was knocked out in the second leadership ballot.
Health secretary Matt Hancock stepped down after recieving 20 votes in the first ballot.
In a video posted to his Twitter page, the politician said he was a candidate "of the future", and it was increasingly clear that the party needed someone that could deal with the "unique circumstances that exist now".
He has not yet announced which of the Tory leadership candidates he will now be backing.
Andrea Leadsom stepped aside to let Mrs May be elected unopposed three years ago.
However this time she did not back down.
Instead, she failed to secure enough votes to keep her in the race in the first round of voting with just 11 votes. A total of 17 were required.
The former Commons leader said she would have been a "decisive and compassionate leader".
The former work and pensions secretary revealed to talkRADIO that she would be running for the Conservative leadership.
The Brexiteer said: "I have always said quite clearly if I got enough support from my colleagues, yes I would.”
"Now people have come forward and I have got that support, so I will be going forward."
The Tatton MP said the Conservative Party needed a leader who "believes in Brexit", and had "belief in the opportunities" it could bring.
She was knocked out in the first round of voting after securing just nine votes.
Former chief whip Mark Harper was one of the less well-known names to have expressed an interest in the top job, and Ladbrokes placed odds of 100/1 on him becoming the next Conservative leader.
Mr Harper worked under Theresa May as immigration minister and was behind the controversial campaign where vans drove around with the slogan "Here Illegally? Go Home or Risk Arrest".
His tenure was cut short after he discovered his self-employed cleaner did not have permission to work in the UK and he went on to hold minister for disabled people and chief whip posts.
He was eliminated from the leadership race after securing 10 votes. Seventeen were required.
James Cleverly was the first candidate to pull out of the Conservative Party leadership race.
He said: "It has become clear that it is highly unlikely that I would progress to the final two candidates.
"For this reason I have withdrawn from the process of selecting a new leader."
Housing minister Kit Malthouse was the second contender to pull out of the race.
The Brexiteer had hoped to take the reins and steer the country away from a no-deal Brexit.
Ex-universities minister Sam Gyimah was the twelfth MP to enter the leadership race, but dropped out after failing to secure the backing of eight MPs.
Of all the candidates, Mr Gyimah was the only one offering a second EU referendum.
The East Surrey MP told Sky News: "It is either no deal or revoke via a second referendum, possibly.
"But what most of the candidates are offering is no deal and a fudge on Theresa May’s deal, which has been heavily defeated.”